From 9df8eb367a0a1da3e6a64113f6a3f74fb1dc9f16 Mon Sep 17 00:00:00 2001
From: Francis Lachapelle <flachapelle@inverse.ca>
Date: Wed, 8 Mar 2017 15:58:47 -0500
Subject: [PATCH] (js) Prevent 304 HTTP status code in IE

Fixes #4066
---
 NEWS                             | 1 +
 UI/WebServerResources/generic.js | 9 +++++++++
 2 files changed, 10 insertions(+)

diff --git a/NEWS b/NEWS
index 9c62f19fd6..75283cd661 100644
--- a/NEWS
+++ b/NEWS
@@ -13,6 +13,7 @@ Bug fixes
  - [eas] improved EAS parameters parsing (#4003)
  - [eas] properly handle canceled appointments
  - [web] fixed SCAYT automatic language selection in HTML editor
+ - [web] prevent 304 HTTP status code for Ajax requests on IE (#4066)
 
 2.3.19 (2017-01-09)
 -------------------
diff --git a/UI/WebServerResources/generic.js b/UI/WebServerResources/generic.js
index e569187c57..f7794d6560 100644
--- a/UI/WebServerResources/generic.js
+++ b/UI/WebServerResources/generic.js
@@ -468,6 +468,15 @@ function triggerAjaxRequest(url, callback, userdata, content, headers, attempt)
         activeAjaxRequests++;
         document.animTimer = setTimeout("checkAjaxRequestsState();", 250);
 
+        if (Prototype.Browser.IE) {
+            // Prevent 304 HTTP status code from the server
+            if (url.indexOf('?') >= 0)
+                url += '&';
+            else
+                url += '?';
+            url += 'nc=' + Math.random();
+        }
+
         http.open(method, url, true);
         http.url = url;
         http.paramHeaders = headers;